1. Field of the Invention
This invention relates to floor elements, as well as to floor coverings which are composed of such floor elements, and to a method for composing such floor elements to a floor covering. The invention also relates to locking systems which can be applied in the aforementioned floor elements.
2. Related Art
More particularly, the invention relates to floor elements, which are intended for forming a floating floor covering and which, during installation, can be coupled at their edges by means of mechanical coupling parts, the latter either being made in one piece with the floor element or not. Such coupling parts can be made such that they provide for a mutual locking of the floor elements in horizontal as well as in vertical direction, for example, as described in the international patent applications WO 94/26999, WO 97/47834, WO 01/98603 and WO 01/96688.
In order to increase the installation comfort of such floor elements, one mostly strives to implement them with relatively large dimensions. To with, large floor elements are more practical to be applied by the user, and composing a floor covering requires less time when the user can start from large floor elements. In connection with the shorter installation time, also the installation cost of such floor covering is lower. By “large floor elements”, substantially floor elements with such a size are meant that they still can easily be handled by a single person. Typical dimensions of such floor elements are, for example, 1200 by 200 millimeters.
However, the fact that smaller floor elements or floor elements with smaller, in particular less wide, decorative parts, in particular when wood parquets or parquet imitations are concerned, are much desired from an esthetically point of view, is contradictory to the aforementioned striving. It is also noted that, although smaller wooden floor elements in respect to material costs per unit of surface area are cheaper than large wooden floor elements, the higher installation costs for smaller floor elements result in that, when the total cost price of the floor covering is brought into account, they will be more expensive than a floor covering composed of large wooden floor elements. Moreover, long, narrow floor elements show the tendency to warp around an axis perpendicular to their decorative side, which leads to problems when installing such floor elements. These problems are very pronounced when the floor elements are installed without glue, i.e., for example, by means of mechanical coupling means, as the aforementioned warping results in difficulties when engaging the coupling means. When installing with glue, when the floor elements are warped, the already installed floor elements have to be strongly tensioned by means of tensioning tools designed especially to this end, which tools as such are known, for example, from WO 99/01629.
In order to offer a solution for the above-mentioned contradictions and problems, rectangular floor elements exist in the state of the art, which as such comprise several decorative portions. Known examples thereof are floor elements which comprise or represent at least two adjacent wooden decorative portions or rows of wooden decorative portions. Depending on the number of such rows, they are called two-planks, three-planks or four-planks. For examples of this solution from the state of the art, reference is made to GB 2 085 357 and WO 93/01378.
The herein above-described rectangular floor elements originating from the state of the art have the disadvantage that it is impossible to compose, starting therefrom, a floor covering with a random bond of decorative parts, as the decorative parts of each time two or more adjacent rows, depending whether a two-plank or a multi-plank, respectively, are concerned, in longitudinal direction of the rows concerned necessarily simultaneously merge into decorative parts of another floor element in the floor covering. The lack of a random bond in such floor covering is seen as disturbing.
The state of the art comprises several suggestions for the improvement of two- or multi-plank elements.
For example, the abovementioned WO 93/01378 suggests matching the decorative parts at the opposing short sides of the rectangular floor elements to each other, such that the motifs of decorative portions, which portions are adjacent to each other, merge into each other where the short sides of two floor elements adjoin each other. It is evident that this technique can only be applied to floor elements with artificially obtained decorative portions, such as decorative portions comprising a printed decor. Moreover, the adaptation of the printed decor in order to obtain such matching is time-consuming and represents a huge restriction of the freedom of design. Also, the lack of a random bond still will be noticeable when, for example, minimal height differences between the different floor elements are present.
In JP 07-076923, EP 1 103 672 and U.S. Pat. No. 4,953,335 is suggested to make the different rows of decorative parts equally long, however, to include them in the floor element at a fixed location in longitudinal direction displaced in relation to each other. The floor elements obtained in this manner are no longer rectangular, but show a pair of stepped opposite sides. However, this suggestion for improving two- or multi-plank elements still has a number of disadvantages. First, the bond which can be obtained by means of such floor elements, still can not relate to a real random bond, as in each case the same step shape would be recognizable in the floor covering, and second, the suggested floor elements, due to their stepped shape, are difficult to package.